Definitions for "Intrados"
Keywords:  voussoirs, soffit, arch, vault, concave
The interior curve of an arch; esp., the inner or lower curved face of the whole body of voussoirs taken together. See Extrados.
The under surface of an arch or vault
The concave curve of an arch. The lower surface of the voussoirs (when in position) of a masonry arch.
Keywords:  bend, arc, inside
The inside arc of the bend.